Treatment of esters with polycarbonates of di (monohydroxyaryl) alkanes



United States Patent 3,390,170 TREATMENT OF ESTERS WITH POLY- CARBONATES 0F DI(MONOHYDROXY- ARYL)ALKANES James K. Sears, Webster Groves, Mo., assignor to Monsanto Company, St. Louis, Mo., a corporation of Delaware No Drawing. Filed Jan. 21, 1965, Ser. No. 427,111 17 Claims. (Cl. 260-475) ABSTRACT OF THE DISCLOSURE This invention relates to the use of polycarbonate resins to reduce the odor of carboxylic acid esters.

This invention relates to a process for the treatment of synthetic plasticizers. More particularly, this invention relates to the treatment of carboxylic acid esters to improve their odor characteristics.

Aliphatic monocarboxylic acid esters, aliphatic polycarboxylic acid esters and aryl carboxylic acid esters and mixtures thereof are widely employed as plasticizers for synthetic resins such as polyvinyl chloride. Although these plasticizers are more than satisfactory in many applications, such plasticizers have been found to have odor characteristics which are of an objectionable nature.

Neutral carboxylic acid esters produced by conventional esterification methods have been generally accepted in the art. However, in using these conventional procedures, the final odor of the product left something to be desired. Odors of unremoved higher molecular weight a1- cohols and decomposition odors which are suggested by higher molecular weight aldehydes could be detected.

As disclosed in the prior art, methods standardly used for removal of odors are somewhat discouraging. Odor masking appears undesirable, as such means merely overcome one odor by superimposing another to create a more compelling olfactory sensation. Additionally, alteration of process conditions in the preparation of such esters has been found to be expensive.

In view of the state of the art, it has become desirable to discover an acceptable process for improving the odor characteristics of the aforcdescribed, widely used plasticizers, thereby increasing the versatility of the application of such plasticizers.

It is therefore an object of this invention to provide a novel method for the treatment of esters of carboxylic acids to improve the odor characteristics thereof.

It is a further object to provide a method for improving the odor characteristics of such aforementioned carboxylic acid esters, which is quick and effective, but yet is sufficiently inexpensive so as to allow its use on a commercial basis.

A still further object is to provide car-boxylic acid esters treated with a polycarbonate resin which afford protection against odor degradation when used as plasticizers for polyvinyl chloride.

These and other objects will readily be seen from the following description and claims.

According to this invention the odor characteristic of carboxylic acid esters selected from the group consisting of:

(a) Esters having up to 22 carbon atoms formed by the reaction of an aliphatic monocarboxylic acid selected from the group consisting of unsubstituted aliphatic monocarboxylic acids and hydroxy substituted aliphatic monocarboxylic acids having from 2 to18 carbon atoms and an alcohol selected from the group consisting of saturated monohydric alcohols having from 1 to 6 carbon atoms, allyl alcohol, alkylene glycols hav- 3,390,170 Patented June 25, 1968 (c) Esters formed by the reaction of an aryl carboxylic acid having from 7 to 10 carbon atoms and an alcohol selected from the group consisting of saturated monohydric alcohols having from 1 to 13 carbon atoms, allyl alcohol, alkylene glycols having from 2 to 6 carbon atoms, glycerol, pentaerythritol, phenol having from 6 to 8 carbon atoms, tetrahydrofurfuryl alcohol, and glycol ethers having from 2 to 8 carbon atoms,

can be greatly improved by contacting said ester with small amounts of a polycarbonate resin.

The method of the invention can be conveniently carried out by adding the polycarbonate resin to the particular carboxylic acid ester to be treated, and agitating for a sufficient length of time at temperatures in the range of 15 C. to C., and preferably 20 10 40 C.

The process of this invention is applicable to a wide variety of carboxylic acid esters. Such esters include the following;

(a) Aliphatic monocarboxylic acid esters, for example, acetates such as glycerol monoacetate, glycerol diacetate, glycerol triacetate and glycerol ether acetate; propionates such as glycerol tripropionate, ethylene glycol dipropionate, diethylene glycol dipropionate and triethylene glycol dipropionate; butyrates such as glycerol butyrate and ethylene glycol dibutyrate; laurates such as n-butyl laurate, ethylene glycol monolaurate, 1,2-propylene glycol monolaurate, diethylene glycol monolaurate, methyl Cellosolve laurate, butyl Cellosolve laurate and polyethylene glycol rn-onolaurate; oleates such as methyl oleate, propyl oleate, isopropyl oleate, butyl oleate, amyl oleate, glycerol monoleate, tetrahydrofurfuryl oleate, ethylene glycol monomethyl ether oleate, ethylene glycol monobutyl ether oleate, diethylene glycol monoleate and 1,2-propylene glycol monoleate; palmitates such as isopropyl palmitate, butyl palmitate, tetrahydrofurfuryl palmitate and methyl Cellosolve palrnitate; ricinoleates such as methyl ricinoleate, butyl ricinoleate, methyl acetyl ricinoleate, n-butyl acetyl ricinoleate, ethylene glycol rinicoleate, propylene glycol rinicoleate, met-hoxyethyl acetyl ricinoleate, diethylene glycol monoricinoleate and glyceryl ricinoleate; and stearates such as butyl stea-rate, 1,2-propylene glycol monostearate and ethylene glycol monoethyl ether stearate;

(b) Aliphatic polycarbo'xylic acid esters, for example, adipates such as diethyl adipate, dibutyl adipate, diiso butyl adipate, di-n-hexyl adipate, di(1,3-dimethyl butyl) adipate, dicapryl adipate, diisooctyl adipate, di(2-ethylhexyl)adipate, n-octyl n-decyl adipate mixture, dinonyl adipate, didecyl adipate, dibenzyl adipate, ditetrahydrofurfuryl adipate, di(butyl Cellusolve)adipate, and di- (butyl Carbitol)adipate; azelates such as diisobutyl azelate, di(2-ethylbutyl)azelate, di(2-ethylhexyl)azelate, diisooctyl azelate and dibenzyl azelate; sebacates and isosebacates such as dimethyl sebacate, diethyl sebacate, dibutyl sebacate, dihexyl sebacate, dioctyl sebacate, diisooctyl sebacate, dicapryl sebacate, dibenzyl sebacate, butyl benzyl sebacate, di(1,3 dimethyl butyllsebacate, dibutoxyethyl sebacate, di(butyl Cellusolve)sebacate and di(Z-ethylhexyl)isosebacate; and citrates such as triethyl O citrate, .tri n-butyl citrate, acetyl triethyl citrate and acetyl tri-n-butyl citrate;

(c) Aryl carboxylic acid esters, for example, benzoates such as diethylene glycol dibenzoate, dipropylene glycol dibenzoate, triethylene glycol dibenzoate, pentaerythritol tetrabenzoate, 3 methyl-1,5-pentanediol dibenzoate and Z-ethylhexyl-poxybenzoate; phthalyl glycollates such as methyl phthalyl methyl glycollate, methyl phthalyl: ethyl glycollate, ethyl phthalyl ethyl glycollate, propyl phthalyl propyl glycollate, butyl phthalyl butyl glycollate, isobutyl phthalyl isobutyl glycollate, hexyl phthalyl hexyl glycollate, cyclohexyl phthalyl cyclohexyl glycollate, Z-ethylhexyl phthalyl 2-ethylhexyl glycollate, decyl phthalyl decyl glycollate, decyl phthalyl 2-ethylhexyl glycollate, dodecyl phthalyl dodecyl glycollate, tridecyl phthalyl tridecyl glycollate, benzyl phthalyl decyl glycollate, phenyl phthalyl ethyl glycollate, tolyl phthalyl ethyl glycollate, xylyl phthalyl ethyl glycollate, benzyl phthalyl ethyl glycollate and tetrahydrofurfuryl phthalyl ethyl glycollate; phthalates and isophthalates such as diethyl phthalate, dipropyl phthalate, dibutyl phthalate, diisobutyl phthalate, diamyl phthalate, dihexyl phthalate, di-n-octyl phthalate, diisooctyl phthalate, dicapryl phthalate, di(2 ethylhexyl) phthalate, dinonyl phthalate, didecyl phthalate, diisodecyl phthalate, butyl isohexyl phthalate, butyl octyl phthalate, butyl decyl phthalate, decyl octyl phthalate, diallyl phthalate, butyl cyclohexyl phthalate, dicyclohexyl phthalate, methylcyclohexyl isobutyl phthalate, di(methylcyclohexyl) phthalate, butyl benzyl phthalate, cresyl benzyl phthalate, benzyl cyclohexyl phthalate, dibenzyl phthalate, glycerol phthalate, dimethoxyethyl phthalate, diethoxyethyl phthalate, dibutoxyethyl phthalate and di(2-ethylhexyl) isophthalate; terephthalates such as diisobutyl terephthalate and di(Z-ethylhexyl)tereplathalate; trimellitates such as trimethyl trimellitate, triethyl trirnellitate, tributyl trimellitate, trihexyl trimellitate, triisooctyl trimellitate, tri-2-ethylhexyl trimellitate and triisodecyl trimellitate; and pyromellitates such as tetramethyl pyromellitate, tetraethyl pyromellitate, tetrabutyl pyromellitate and tetrahexyl pyromellitate.

The term polycarbonate resin, as used herein, is meant to designate resins of linear aliphativ, cycloaliphatic and aromatic polyesters of carbonic acid. These polycarbonates may be produced from a great number of aliphatic, cycloaliphatic and aromatic dihydroxy compounds.

Illustrative of the aliphatic dihydroxy compounds which can be employed are ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, thioglycol, ethylene dithioglycol, 1,3-propanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol. Illustrative of cycloaliphatic dihydroxy compounds are 1,4- cyclohexanediol, 1,2 cyclohexanediol, 2,2-(4,4-dihydroxydicyclohexylene)propane and 2,6 dihydroxydecahydronaphthalene. Illustrative of the aromatic dihydroxy compounds are hydroquinone, resorcinol, pyrocatechol, 4,4 dihydroxydiphenyl, 1,6 dihydroxynaphthalene, 2,6 dihydroxynaphthalene, 1,4 dihydroxynaphthalene, 1,5 dihydroxynaphthalene, dihydroxyanthracene, 2,2- dihydroxydinaphthyl 1,1 and o,rn,p hydroxybenzyl alcohol and the like; di(monohydroxyaryl)sulfones such as di(4 hydroxyphenyl)sulfone, di(2 hydroxyphenyl) sulfone, di(3 hydroxyphenyDsulfone, di(4 -'hydr0xy- 2 methylphenyDsulfone, di(4 hydroxy-B-methylphenyl)sulfone, di(2 hydroxy 4 methylphenyl)sulfone, di(4 hydroxy 2 ethylphenyl)sulfone, di(4-hydroxy- 3 ethylphenyDsulfone, di(4 hydroxy-2-tert.-butylphcnyl)sulfone, di(4 hydroxy 3 tert. butylphenyl) sulfone,di(2 hydroxy-l-naphthyl)sulfone, and the like.

Di(rnonohydroxylaryl)alkanes such as:

1,1-di (4-hydroxyphenyl)ethane, 1.,l-di(4-hydroxyphenyl)propane, 1,1-di(4-hydroxyphenyl)butane, 1,1-di(4-hydroxyphenyl)-2-methylpropane,

'4 1,1-di(4-hydroxyphenyl)heptane, 1,1-di(4-hydroxyphcnyl)-l-phenylmethane,

di (4-hydroxyphenyl) 4-methylphenylmethane,

di (4-hydroxyphenyl) -4-ethylphenylmethane,

di (4-hydroxyphenyl) -4-isopropylphenylmeth ane,

di (4-hydroxyphenyl -4-butylphenylrnethane, v

di (4-hydroxyphenyl benzylmethane,

di(4-hydr0xyphenyl)-a-furylmethanc,

2,2-di (4-hydroxyphenyl octane,

2,2-di (hydroxyphenyl nonane,

di (4-hydroxyphenyl l -a-furylethane,

1, l-di (4-hydroxyphenyl )cyclopentane,

2,2-di (4-hydroxyphenyl) decahydronaphthalene,

2,2-di (4-hydroxy-3-cyclohexylphenyl propane,

2,2-di (4-hydroxy-3-isopropylphenyl) butane,

1, l-di 4-hydroxy-3-methylphenyl cyclohexane,

2,2-di (4-hydroxy-3-butylphenyl) propane,

2,2-di (4-hydroxy-3-phenylphenyl) propane,

2,2-di (4-hydroxy-2-methylphenyl propane,

1', 1-di( 4-hydroxy-3-methyl-6-butylphenyl butane,

1, l-d-i 4-hydroxy-3-methyl-6-tert.-butylphenyl ethane,

1, 1-di 4-hydroxy-3 -methyl-6-tert.-buty1phenyl propane,

1 1 -di( 4-hydroxy-3-methy1-6-tert.-butylphenyl) butane,

1,1-di 4-hydroxy-3-rnethyl-6-tert.-butylphenyl isobutane,

l,1-di(4-hydroxy-3 -methyl-6-tert.-butylphenyl )heptane,

1,1-di(4-hydroxy-3-methyl-6-tert.-butylphenyl)-1-phenylmethane,

1,1-di(4-hydroxy-3-methyl-6-tert.-butylphenyl)-2-methyl- 2-pentane,

l,1-di(4-hydroxy-3-methyl-6-tert.-butylphenyl)-2-ethyl-2- hexane,

1,1-di(4-hydroxy-3-methyl-6-tert.-amylphenyl)butane,

di(4-hydroxyphenyl methane,

2,2-di 4-hydroxyphenyl propane,

1,1-di(4-hydroxyphenyl)cyclohexane,

1, 1 -di( 4-hydroxy-3-methylphenyl )cyclohexane,

1, 1 -di( 2-hydroxy4-methylphenyl) butane,

2,2-di (2-hydroxy-4-tert.-butylphenyl) propane,

1,1-di(4-hydroxyphenyl)-1-phenylethane,

2,2-di (4-hydroxyphenyl )butane,

2,2-di 4-hydroxyphenyl pentane,

3 ,3-di(4-hydroxyphenyl pentane,

2,2-di (4-hydroxyphenyl hexane,

3,3-di 4-hydroxyphenyl hexane,

2,2-di (4-hydroxyphenyl -4-methyl,pentane,

2,2-di (4-hydroxyphenyl )heptane,

4,4-di 4-hydroxyphenyl )heptane,

2,2-di 4-hydroxyphenyl tridecane,

2,2-di(4-hydroxy-3-methylphenyl) propane,

2,2-di 4-hydroxy-3-methyl-3 '-isopropylphenyl butane,

2,2-di 3 ,5 -dichloro-4-hydroxyphenyl propane,

2,2-di 3,5 -dibromo-4-hydr0xyphenyl propane,

di( 3-chloro-4-hydroxyphenyl )methane,

di 2-hydroxy-5-fiuorophenyl methane,

di (4-hydroxy-phenyl phenylrnethane,

1,1-di(4-hydroxyphenyl)-1-phenylethane, and the like.

The preferred class of dihydroxy compounds for use in the practice of this invention are the aromatic dihydroxy compounds and in particular the di(monohydroxyaryl)alkanes.

Polycarbonates of the aforesaid di(monohydroxyaryl)- alkanes can be prepared by a number of methods known to those skilled in the art. For example, the di(monohydroxyaryl)alkanes can be re-esterified with carbonic acid diesters, e.g. dimethyl-, diethyl-, dipropyl-, dibutyl-, diamyl-, dioctyl-, dicyclohexy1-, diphenyl-, and di-o,p-tolylcarbonate and the like, at elevated temperatures of from about C. to about 320 C.

Another method available for the preparation of polycarbonates involves the introduction of phosgene into solutions of di(monohydroxyaryl)alkanes in organic bases, such as dirnethylaniline, diethylaniline, trimethylaniline, pyridine and the like or into solutions of di(monohydroxyaryDalkanes in different organic solvents such as ligroin, cyclohexane, methylcyclohexane, benzene toluene, xylene, chloroform, methylene chloride, carbon tetrachloride, trichloroethylene, dichloroethane, methyl acetate, ethyl acetate and the like, with the addition of an acid-binding agent, e.g., a tertiary amine.

Still another suitable process for producing polycarbonates comprises introducing phosgene into the aqueous solution or suspension of alkali metal salts such as l-ithium, sodium, potassium, and calcium salts of the di(monohydroxyaryDalkanes, preferably in the presence of an excess of a base such as lithium, sodium, potassium, and calcium hydroxide or carbonate. The polycarbonates precipitate from the aqueous solution.

The di(monohydroxyaryl)alkanes can be reacted with bischlorocarbonates of di(monohydroxyaryl)alkanes in the presence of inert solvents and acid-binding materials, e.g., tertiary amines.

The amount of polycarbonate resin employed can be varied; however, for efiicient treatment, amounts varying from about 0.10% to about 3.0% by weight, based on the weight of the ester, will provide excellent results. A significant improvement in odor characteristics can be effected, however, by the use of small amounts of at least 0.01%. Much larger amounts as high as 20.0% can be used. 1

The following examples illustrate the advantageous and unexpected results which are achieved by the use of the polycarbonate resin of this invention, but it is not intended that this invention be limited by or to the examples.

EXAMPLE 1 Into a suitable reaction vessel, having means for the addition and removal of liquids, means for agitating the vessel contents, means for heating and cooling the vessel contents, and means for measuring the temperature of the liquids in the vessel, there is charged 100.0 grams of butyl phthalyl butyl glycollate. There is then added 1.0 gram polycarbonate of 2,2-di(4-hydroxyphenylpropane), and the resulting mixture is agitated for about one hour at room temperature. The treated ester upon oven aging for fourteen days at 115 C. is found to be bland, whereas the untreated crude esters aged under the same conditions is odoriferous.

EXAMPLE 2 EXAMPLE 3 Following the procedure of ExampleZ, 100 grams of di-2ethylhexyl adipate is treated with 0.5 gram of the polycarbonate of 2,2-di(4-hydroxyphenyl)propane. A marked improvement in the odor of the treated ester is obtained when compared with the corresponding crude.

EXAMPLE 4 Following the procedure of Example 1, 60.0 grams of isopropyl oleate is treated with 0.20 grams of the polycarbonate of 2,2-di(4-hydroxyphenyl)propane. It is found that the odor of the treated ester, compared with the cor responding crude, is materially lessened.

EXAMPLE 5 Following the procedure of Example 1, 50.0 grams of butyl benzyl phthalate is treated with 0.5 grams of 2,2 di(4-hydroxyphenyl) propane. The treated ester is essentially free of odor.

EXAMPLE 6 Following the procedures of Example 2, 50.0 grams of diethylene glycol dipropionate is treated with 0.25 gram of the polycarbonate of 2,2-di(4-hydroxyphenyl) propane.

The treated ester shows a marked improvement in odor when compared to the corresponding crude.

EXAMPLES 7-l 8 Ex. N0. Ester Treated Treating Agent 7 Glycerol ether acetate t. Polycarbonate resin. 8 Ethylene glycol dibutyrate Do. 9 Methyl cellulose laurate D0. 10,. Tetrahydrofurfuryl oleate Do. 11.. Butyl ricinoleate Do. 1Z Ethylene glycol monoethyl ether stearate Do. 13. s. Dibenzyl axelate Do. 14 Acetyl tri-n-citrate Do. 15 2titilylhexyl phthalyl Z-ethylhexyl glyeol- Do.

a e Diallyl phthalate Do. Tributyl trimellitate. Do. 18 Tetrahexyl pyromellitate Do.

1 Polycarbonate of 2,2-di (-hydroxyphenyl) propane.

Each of the esters, when compared with the crude, is of a markedly improved odor.

EXAMPLE 19 Following the procedure of Example 2, 20 grams of tetrahydrofurfuryl palmitate is treated with 0.2 gram of the polycarbonate of 2,2-di(4-hydroxyphenyl)propane. It is found that the odor of the treated ester, compared with the corresponding crude is materially lessened.

EXAMPLE 20 Following the procedure of Example 1., 50.0 grams of diisodecyl phthalate is treated with 0.5 gram of the polycarbonate of 2,2 di(4-hydroxyphenyl) propane. The treated ester is essentially free of odor.

EXAMPLE 21-26 Following the procedure of Example 2, 50.0 grams of each of the carboxylic acid esters tabulated below is substituted for the di-Z-ethylhexyl isophthalate.

EXAMPLE 27 1 Into a suitable reaction vessel (as previously described in Example 1), there is charged 100.0 gra ns of butyl phthalyl butyl glycollate. There is then added 2.0 grams polycarbonate of 2,2-di(4-hydroxyphenylpropane), and the resulting mixture is agitated for about'one hour at room temperature. The treated ester upon oven aging for twenty-two hours at C. is iound to be bland, whereas the untreated crude ester aged under the same conditions is odoriferous.

Equally sat-isfiactory and advantageous results are obtained upon replacing the polycarbonate resin used in the aforedescribed examples with other polycarbonate resins obtained from di(monohydroxyaryl)alkanes such as di 4-hydroxyphenyl methane,

1,1 -di(4-hydroxyphenyl) ethane, 1,1-di(4-hydroxyphenyl) propane, 1,l-di(4-hydroxyphenyl)butane,

l, 1 -di 4-hydroxyphenyl isobutane, 1,1-di(4-hydroxyphenyl) cyclopentane, 1,1 -di 4-hydroxyphenyl cyclohexane, 2,2-di(4-bydroxyphenyl butane, 2,2-di (4-hydroxyphenyl pentane, 2,2-di(4-hydroxyphenyl)hexane, 2,2-di(4-hydroxyphenyl)heptane, 2,2-di(4-hydroxyphenyl)octane, 2,2-di(4-hydroxyphenyl)nonane, 3,3-di(4-hydroxypheny1)pentane, 4,4-di 4-hydroxyphenyl) heptane.

When the carboxylic acid esters treated with a polycarbonate resin are used to plasticize vinyl chloride resins the protection against odor degradation is maintained. Additionally, the plasticized resin retains its color characteristics, tensile strength and elongation, particularly at high temperatures.

EXAMPLE 28 The compositions whose formulations are shown below in Table I were each mixed on a rolling mill for three to five minutes at 170 C. to a uniform blend. Data obtained upon testing of the molded sheet which is oven aged at 115 C. for days is shown in Table I wherein all proportions are in parts by weight.

Polyvinyl chloride... 100 100 100 100 Diisodecyl phthalate. 50 50 Polucarbonate resin. 0. 5 1. 0 10 Epoxidized Soya Bean Oil 3 3 3 3 Barium-cadmium Stabilizer 2 2 2 2 Properties: 70 65 Color with tri-blue filter:

Transmission (percent):

Days:

1 63 57 59 52 2 6 15 28 5 0 0.5 0.5 Tensile Strength (p.s.i.):

Days:

0 2, son 3, 000 2, 900 2, 800 1 2,100 2,100 2, 300 2, 500 2 1, 900 2,100 .2, 2, 000 5 2, 200 2,100 2, 000 3, 0110 Modulus (100%):

Days:

The data of Table I clearly shows that a polyvinyl chloride resin plasticized with an ester treated with a polycarbonate resin retains its tensile properties. Protection against odor degradation is found to be maintained and color development is retarded.

EXAMPLE 29 One hundred parts by weight of polyvinyl chloride, 50 parts by weight of butyl phthalyl butyl glycollate, 1.0 part by Weight of a polycarbonate of 2,2-di(4-hydroxyphenyl)propane and 1.0 part of a calcium-zinc stabilizer are mixed on a rolling mill at C. to a uniform blend. Upon oven aging the composition at 150 C. for one and one-half hours, it is found the excellent odor characteristics, which are obtained by treating the plasticizing ester with a polycarbonate resin, are retained when incorporated into a polyvinyl chloride composition. In comparison, such an untreated ester retains its odoriferous characteristics in similar polyvinyl chloride compositions.

EXAMPLE 30 One hundred parts by weight of polyvinyl chloride, 55 parts by weight of butyl phthalyl butyl glycollate and 10.0 parts by weight of a polycarbonate of 2,2-di(4-hydroxyphenyl) propane are mixed on a rolling mill at 170 C. to a uniform blend. Upon oven aging the comparison at 150 C. for one and one-half hours, it is found the excellent odor characteristics, which are obtained by treating the plasticizing ester with a polycarbonate resin, are retained when incorporated into a polyvinyl chloride composition. In similar polyvinyl chloride compositions, the untreated ester retains its odoriferous characteristics.

From the foregoing results, it is evident that the odor characteristics of the aforedescribed esters can be significantly improved by treatment wiht a polycarbonate resln.

While this invention has been described with respect to certain embodiments, it is not so limited, and it is to be understood that variations and modifications thereof, which are obvious to those skilled in the art, may be made without departing from the spirit or scope of this invention.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A process which comprises contacting a carboxylic acid ester selected from the group consisting of:

(a) esters having up to 22 carbon atoms formed by the reaction of an aliphatic monocarboxylic acid selected from the group consisting of unsubstituted aliphatic monocarboxylic acids and hydroxy substituted aliphatic monocarboxylic acids having from 2 to 18 carbon atoms and an alcohol selected from the group consisting of saturated monohydric alcohols having from 1 to 6 carbon atoms, allyl alcohol, alkylene glycols having from 2 to 8 carbon atoms, glycerol, tetrahydrofurfuryl alcohol, and glycol ethers having from 2 to 8 carbon atoms;

(b) esters formed by the reaction of an aliphatic polycarboxylic acid selected from the group consisting of unsubstituted aliphatic polycarboxylic acids and hydroxy substituted aliphatic polycarboxylic acids having from 6 to 10 carbon atoms and an alcohol selected from the group conissting of saturated monohydric alcohols having from 1 to 11 carbon atoms, allyl alcohol, tetrahydrofurfuryl alcohol and glycol ethers having from 2 to 8 carbon atoms; and

(c) esters formed by the reaction of an aryl carboxylic acid having from 7 to 10 carbon atoms and an alcohol selected from the group consisting of saturated monohydric alcohols having from 1 to 13 carbon atoms, allyl alcohol, alkylene glycols having from 2 to 6 carbon atoms, glycerol, pentaerythritol, phenol having from 6 to 8 carbon atoms, tetrahydrofurfuryl alcohol, and glycol ethers having from 2 to 8 carbon atoms;

with a polycarbonate of a di(monohydroxyaryl)alkane in the amount of from about 0.01% to about 20.0% by weight of the ester.

2. A process which comprises contacting a carboxylic acid ester selected from the group consisting of:

(a) esters having up to 22 carbon atoms formed by the reaction of an aliphatic monocarboxylic acid selected from the group consisting of unsubstituted aliphatic monocarboxylic acids and hydroxy substituted aliphatic monocarboxylic acids having from 2 to 18 carbon atoms and an alcohol selected from the group consisting of saturated monohydric alcohols having from 1 to 6 carbon atoms, allyl alcohol, alkylene glycols having from 2 to 8 carbon atoms, glycerol, tetrahydrofurfuryl alcohol, and glycol ethers having from 2 to 8 carbon atoms;

(b) esters formed by the reaction of an aliphatic polycarboxylic acid selected from the group consisting of unsubstituted aliphatic polycarboxylic acids and hydroxy substituted aliphatic polycarboxylic acids having from 6 to 10 carbon atoms and an alcohol selected from the group consisting of saturated monohydric alcohols having from 1 to .11 carbon atoms, allyl alcohol, tetrahydrofurfuryl alcohol and glycol ethers having from 2 to 8 carbon atoms; and

(c) esters formed by the reaction of an aryl carboxylic acid having from 7 to 10 carbon atoms and an alcohol selected from the group consisting of saturated monohydric alcohols having from 1 to 13 carbon atoms, allyl alcohol, alkylene glycols having from 2 to 6 carbon atoms, glycerol, pentaerythritol, phenol having from 6 to 8 carbon atoms, tetrahydrofurfuryl alcohol, and glycol ethers having from 2 to 8 carbon atoms;

7 with a polycarbonate of a di(monohydroxyaryl)alkane in the amount of from about 0.10% to about 3.0% by weight of the ester.

3. A process of claim 2 wherein the polycarbonate of a di(n1onohydroxyaryl)alkane is a polycarbonate of 1,1- di (4-hydroxyaryl) alkane.

4. A process of claim 3 wherein the polycarbonate of a 1,1-di(4-hydroxyaryl)alkane is a polycarbonate of l,1di(4-hydroxyphenyl)propane.

5. A process of claim 3 wherein the polycarbonate of a 1,1-di(4-hydroxyaryl)alkane is a polycarbonate of 1,1- di (4-hydroxyphenyl cyclohexane.

' 6. A process of claim 2 wherein the polycarbonate of a di(monohydroxyaryl)alkane is a polycarbonate of a 2,2di (4-hydroxyaryl) alkane.

7. A process of claim 6 wherein the polycarbonate of a 2,2-di(4-hydroxyaryl)alkane is a polycarbonate of a 2,2-di (4-hydroxyphenyl propane.

8. A process which comprises contacting an aliphatic inonocarboxylic acid ester having up to 22 carbon atoms formed by the reaction of an aliphatic monocarboxylic acid selected from the group consisting of unsubstituted aliphatic monocarboxylic acids and hydroxy substituted aliphatic monocarboxylic acid having from 2 to 18 carbon atoms and an alcohol selected from the group con sisting of saturated monohydric alcohols having from 1 to 6 carbon atoms, allyl alcohol, alkylene glycols having from 2 to 8 carbon atoms, glycerol, tetrahydrofurfuryl alcohol, and glycol ethers having from 2 to 8 carbon atoms, with a polycarbonate of a 2,2-di(4-hydroxyarylalkane) in the amount of from 0.10% to about 3.0% by weight of said ester.

9. A process which comprises contacting an aliphatic polycarboxylic acid ester formed by the reaction of an aliphatic polycarboxylic acid selected from the group consisting of unsubstituted aliphatic polycarboxylic acids and hydroxy substituted aliphatic polycarboxylic acids having from 6 to 10 carbon atoms and an alcohol selected from the group consisting of saturated monohydric alcohols having from 1 to 11 carbon atoms, allyl alcohol, tetrahydrofurfuryl alcohol and glycol ethers having from 2 to 8 carbon atoms, with a polycarbonate of a 2,2-di(4-hydroxyarylalkane) in the amount of from 0.10% to about 3.0% by weight of said ester.

10. A process which comprises contacting an arylcarboxylic acid ester formed by the reaction of an aryl carboxylic acid having from 7 to 10 carbon atoms and an alcohol selected from the group consisting of saturated monohydric alcohols having from I to 13 carbon atoms, allyl alcohol, alkylene glycols having from 2 to 6 carbon atoms, glycerol, pentaerythritol, phenol having from 6 to 8 carbon atoms, tetrahydrofurfuryl alcohol, and glycol ethers having from 2 to 8 carbon atoms, with a polycarbonate of a 2,2-di(4-hydroxyarylalkane) in the amount of from about 0.10% to about 3.0% by weight of said ester.

,11. A process comprising contacting di-2-ethylhexyl phthalate with a polycarbonate of 2,2-di(4-hydroxyphenyl)propane in an amount of from about 0.10% to about 3.0% by weight of said ester.

12. A process comprising contacting butyl phthalyl butyl glycollate with a polycarbonate of 2,2-di(4-hydroxyphenyl)propane in an amount of from about 0.10% to about 3.0% by weight of said ester.

13. A process comprising contacting di-Z-ethyl hexyl adipate with a polycarbonate of 2,2-di(4-hydroxyphenyl) propane in an amount of from about 0.10% to about 3.0% by weight of said ester.

14. A process comprising contacting diisodecyl phthalate with a polycarbonate of 2,2-di(4-hydroxypheny1) propane in an amount of from about 0.10% to about 3.0% by weight of said ester.

15. A process comprising contacting dipropylene glycol dibenzoate with a polycarbonate of .2,2-di(4-hydroxyphenyl)propane in an amount of from about 0.10% to about 3.0% by weight of said ester.

16. A process comprising contacting butyl benzyl phthalate with a polycarbonate of 2,2-di(4-hydroxyphenyl) propane in an amount of from about 0.10% to about 3.0% by weight of said ester.

17. A process comprising contacting diethylene glycol dipropionate with a polycarbonate of 2,2-di(4-hydroxyphenyl)propane in an amount of from about 0.10% to about 3.0% by weight of said ester.

References Cited UNITED STATES PATENTS 3,014,064 12/1961 Evenhuis et a1. 260--485 LORRAINE A. WEINBERGER, Primary Examiner.

T. L. GALLOWAY, Assistant Examiner. 

